CHARACTERIZATION OF FLOWERING TIME GENES IN ALFALFA FOR CROP IMPROVEMENT

CERDAN, PABLO DIEGO; ESTEFANIA MANCINI; ANTONIETTI, MARIANA SOFÍA; JAVIER ISERTE; CARLOS DEZAR; CHRISTIAN DAMIAN LORENZO; MARCELO YANOVSKY; MARTÍN VÁZQUEZ; MAXIMILIANO SANCHEZ LAMAS

Workshop; SIGNAT workshop on environmental regulation of plant development; 2017

SIGNAT

CHARACTERIZATION OF FLOWERING TIME GENES IN ALFALFA FOR CROP IMPROVEMENTChristian Lorenzo1, Maximiliano Sánchez-Lamas1, Mariana Antonietti1, Carlos Dezar2, Martín Vázquez2, Estefanía Mancini1, Javier Iserte1, Marcelo Yanovsky1, Pablo Cerdán1.1 Instituto Leloir; IIBBA-CONICET.2 INDEAR (Instituto de Agrobiotecnología de Rosario).pcerdan@leloir.org.arMedicago sativa (alfalfa) is one of the most important forage crops worldwide. It is appreciated for its high quality which includes higher palatability, higher protein content and digestibility. As a leguminous plant, it is also appreciated for its ability to fix nitrogen through Rizhobium symbiosis.However, programs to increase yield and quality have had relative success. Alfalfa is a tetraploid species with high resistance to inbreeding, and therefore relatively difficult to improve. As with other forage crops, alfalfa quality decreases with flowering and consequently impacts on dairy and meatproduction. On the other hand, shade avoidance responses also decrease the ratio of leaf to stem tissues, decreasing forage quality. We aimed at generating new tools for alfalfa improvement. Using a partial draft sequence of the genome, we identified genes coding for photoreceptors and flowering time genes based onsimilarities to known genes in model species. We isolated three PHYTOCHROME genes, five genes of the FLOWERING LOCUS T family and three genes of the TERMINAL FLOWER1 family. We tested their function in Arabidopsis thaliana. One of the msFT genes promoted flowering in both long and short days. On the contrary, one of the msTFL1 genes delayed flowering when overexpressed. Thethree phytochromes delayed flowering in a phytochrome-less background in Arabidopsis. We generated transgenic lines overexpressing msTFL1, phytochromes A and B and downregulating msFT. These lines showed delayed flowering and a higher number of nodes to flowering, increasing the leaf to stem ratios. We propose these lines could be used in alfalfa breeding programs to increase forage quality.Acknowledgements. APCyT for funding.